<template>
  <div>
    <div class="btn-box">
      <div @click="change"><i class="fa fa-moon-o" aria-hidden="true"></i> 切换  {{ flag ? '黑夜' : '白天' }} </div>
    </div>
    <div :class="flag ? 'light' : 'dark'" id="container">
      <div class="bg"></div>
      <div class="moon-box">
        <div class="moon"></div>
      </div>
      <div class="sun-box">
        <div class="sun"></div>
      </div>
      <div class="sea"></div>
    </div>
  </div>
</template>

<script setup lang="ts">
import { ref } from "vue"

let flag = ref(false);

const change = () => {
  flag.value = !flag.value;
};
</script>

<style scoped>
body {
  /* 初始化 取消内外边距 */
  margin: 0;
  padding: 0;
}
#container {
  /* 100%窗口高度 */
  height: 100vh;
}
.bg {
  /* 绝对定位 */
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}
.sun {
  margin: 0;
  padding: 0;
  /* 绝对定位 水平垂直居中 */
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background-color: orange;
  border-radius: 50%;
}
.moon {
  margin: 0;
  padding: 0;
  /* 绝对定位 水平垂直居中 */
  position: absolute;
  top: 50%;
  left: 50%;
  /* 计算得出月亮的位置 */
  transform: translate(calc(-50% + -160px), calc(-50% + -180px));
  width: 600px;
  height: 600px;
  /* 通过阴影绘制月亮 */
  box-shadow: 160px 180px 0 cyan;
  border-radius: 50%;
}
.sea {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 35%;
  /* 背景模糊制造大海的感觉 */
  backdrop-filter: blur(100px);
  -webkit-backdrop-filter: blur(100px);
  z-index: 100;
}
.sun,
.moon,
.sun-box,
.moon-box,
.bg {
  /* 添加动画过渡 */
  transition: all 1s ease-in-out;
}
.sun-box,
.moon-box {
  /* 相对定位 */
  position: relative;
  /* 溢出隐藏 */
  overflow: hidden;
}
/* 白天 */
.light .sun-box {
  height: 100%;
}
.light .moon-box {
  height: 0;
}
.light .bg {
  background-color: #ffeea2;
}
/* 夜晚 */
.dark .sun-box {
  height: 0;
}
.dark .moon-box {
  height: 100%;
}
.dark .bg {
  background-color: #040720;
}
/* 切换按钮样式 */
.btn-box {
  position: absolute;
  top: 5px;
  left: 5px;
  z-index: 101;
  display: flex;
  flex-direction: row;
}
.btn-box div {
  background: rgba(255, 255, 255, 0.7);
  color: #000;
  width: 90px;
  height: 40px;
  line-height: 40px;
  text-align: center;
  margin: 5px;
  font-size: 14px;
  border-radius: 5px;
  cursor: pointer;
}
.btn-box div:hover {
  background: #fff;
}
</style>
